The relationship between the Broca-Sulzer effect and visually evoked potentials (VEPs) was examined with two subjects. In the psychophysical experiment, a flash of disc subtending 52′ in visual angle and of one of the 11 durations ranging from 0 (no stimulus) to 1000 ms was presented by means of a Maxwellian view system. The luminance levels were at 312, 987, and 3120 cd/m
2. Brightness judgments were made with the method of magnitude estimation. In the VEP experiment, 300-summed VEPs were obtained from 0
1 in the 10-20 system at six durations ranging from 0 to 500 ms and at 312 and 3120 cd/m
2. As to the VEP components (P
1, N
1, P
2, N
2), two indices of the areas ΔP
1N
1P
2 and ΔN
1P
2N
2 were measured with a planimeter and were used for the analysis. The results indicated the positive correlation between the apparent brightness enhancement and the VEP responses.
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